I have several queries regarding UV lamp. If I use a 10W UV lamp in 1L water container, how to calculate UV light intensity of a specific wave length (eg 254 nm) in a 1 L volume.
I also need to know the difference between power intensity and power density. Considering the information I found, there is no difference as most of the UV lamps are used for surface disinfection, thus the power density and the intensity looks the same, as it calculates for unit area (uW/cm2).
If I use a 10W UV lamp in a 1 L water sample for 8 hours, the power density is 10 W/L. and the energy density is 10*8*60*60J/L
What is the difference between UV dose and energy density?
If I use a glass jar as my sample container, is there a loss of UV energy due to UV light penetration from the glass wall.
Greatly appreciate your advice.
1) Different UV lamps have different spectral distributions, so unless there is a datasheet from the manufacturer, you will have to measure energy distribution over the spectrum using a calibrated spectrometer.
2) A density is a spatial distribution of power or energy over a defined volume. There are various dosis terms defined in radiation science:
a) Energy dose is the uptaken energy per mass, unit 1J/kg=1Gray
b) Kerma is the "kinetic energy released per unit mass", unit also Gray
c) when it comes to health implications, there would also be the equivalent dose, the organ dose and the effective dose. They share the unit Sievert (Sv) which is also J/kg but due to the different normalization a Gray energy dose and an Sv equivalent dose may differ substantially.
[d) technically not a dose, but often mentioned along with the doses is the capture cross section which is measured in 1barn=10-28m2]
Now, I've never seen any other than a+b being applied to soft UV radiation, but I think it's important to specify what kind of dose one wants to talk about.
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